Thermophysical properties of meat In chilling, freezing, thawing and tempering processes heat has either to be introduced or to be extracted from the meat to change its temperature The rate at which heat can be removed or introduced into the surface of meat is essentially a function of the process being used, for example air blast, plate, immersion, and so on. However, the rate at which heat can flow from within the meat to its surface is a function of the thermophysical prop- erties of the meat. If we continue to

Since the mid-1980s there has been a considerable increase in legislation defining maximum temperatures during the production, distribution and retailing of chilled food. However, as soon as the food is purchased by the consumer, it is outside of any of these legislative requirements. Increasingly food poisoning incidents have been found to be due to mishandling of food in the home with insufficient refrigeration or cooling being the most fre

In general, display cabinets have to accommodate three types of meat and meat products: (1)chilled wrapped, (2) chilled unwrapped and (3)frozen wrapped products. The required display life and consequent environmental conditions for wrapped chilled products differ from those for unwrapped products. The desired chilled display life for wrapped meat and meat prod- ucts ranges from a few days to many weeks and is primarily limited by microbiological considerations. Retailers of unwrapped meat and deli

Theoretically, there are clear differences between the environmental con- ditions required for cooling, which is a heat removal/'temperature reduction process, and those required for storage where the aim is to maintain a set product temperature. However, in many air-based systems, cooling and storage take place in the same chamber and even where two separate facil- ities are used, in many cases not all the required heat is removed in the

Developments in frozen transport in the 19th century established the inter- national food market. In 1877, a cargo of frozen meat was sent from Buenos Aires to France. The following year 5000 frozen mutton carcasses were transported from Paraguay to France. In 1880, the SS Strathleven arrived in London with a cargo of 40 tons of frozen Australian beef, and by 1910

Thawing has received much less attention in the literature than either chill- ing or freezing. In commercial practice there are relatively few controlled thawing systems. Frozen meat, as supplied to the industry, ranges in size and shape from complete hindquarters of beef to small breasts of lamb, although the major- ity of the material is 'boned-out' and packed in boxes ca. 15 cm thick weigh- ing between 20 and 40kg. Thawing is usually regarded as complete when the centre of the block or joint has

leat for industrial processing is usually frozen in the form of carcasses, quarters or boned out primals in 25 kg cartons. Most bulk meat, consumer portions and meat products are frozen in air blast freezers. Some small ind viduals items, for example beefburgers, may be frozen in cryogenic tunnels and a small amount of offal and other meat is frozen in plate freezers. It is not unusual for meat to be frozen twice before it reaches the consumer During industrial processing frozen raw material is often thawed or tem-

The increased application of temperature legislation in many countries. coupled with economic requirements to maximise throughput, minimise weight loss and operate refrigeration systems in the most efficient manner, has created a very large demand for process design data on all aspects of

From the moment an animal is slaughtered the meat produced begins to lose weight by evaporation. Under typical commercial distribution condi tions, it has been estimated that lamb and beef lose from 5.5 to 7% by evap- oration between slaughter and retail sale(Malton, 1984). Weight losses from pork are probably of the same magnitude. In addition to the direct loss in saleable meat there are also secondary

The appearance of meat at its point of sale is the most important quality attribute governing its purchase. The ratio of fat to lean and the amount of marbled fat are important appearance factors and another is the colour of the meat. The changes in colour of the muscle and blood pigments (myoglobin and haemoglobin, respectively) determine the attractiveness